Behaviour of human articular chondrocytes during in vivo culture in closed, permeable chambers.

MedLine Citation:

PMID:
22862838
Owner:
NLM
Status:
Publisher

Abstract/OtherAbstract:

The exact contribution of transplanted chondrocytes for cartilage tissue repair prior expansion in monolayer cultures remains undetermined. At our laboratory we have created a new permeable chamber to study the chondrogenesis of de-differentiated cells implanted ectopically in a closed and controlled environment. The behavior of chondrocytes has been studied in settings frequently used in clinical approaches during transplantation, namely injection of autologous chondrocyte cells in suspension (ACI), cells soaked in collagen membranes (MACI), and cells applied in a polymer gel (fibrin). As controls we have tested the re-differentiation of chondrocytes in cell aggregates and we have checked the proper functionality of chambers both in vitro and in vivo. After retrieval, firmed tissue-like shapes were recovered only from chambers containing cells seeded in membranes. Histo-morphological, immunohistochemical and ultrastructural analyses revealed synthesis of fibrous-like tissue, characterized by low density of collagen fibres, low collagen type II, abundant collagen type I, and low amounts of proteoglycans. Additionally, neither the collagen membranes nor the fibrin gel were reabsorbed by cells. In summary, our results show that the newly developed permeable chambers function correctly, allowing proper cell feeding and preventing cell leakage or host cell invasion. Additionally, our results suggest that under these circumstances chondrocytes are not able to orchestrate formation of hyaline cartilage and have little capacity to degrade artificial membranes or carrier gels such as fibrin. These are interesting observations that should be considered for understanding what role play the transplanted chondrocytes during restoration of articular cartilage after implantation.